Problem: Recently, Anton has found a set. The set consists of small English letters. Anton carefully wrote out all the letters from the set in one line, separated by a comma. He also added an opening curved bracket at the beginning of the line and a closing curved bracket at the end of the line. 

Unfortunately, from time to time Anton would forget writing some letter and write it again. He asks you to count the total number of distinct letters in his set.

Input

The first and the single line contains the set of letters. The length of the line doesn't exceed 1000. It is guaranteed that the line starts from an opening curved bracket and ends with a closing curved bracket. Between them, small English letters are listed, separated by a comma. Each comma is followed by a space.

Output

Print a single number — the number of distinct letters in Anton's set.

Examples

Input

{a, b, c}


Output

3


Input

{b, a, b, a}


Output

2


Input

{}


Output

0

Solution (in JAVA):

Solution:
/* Author : DEBOJYOTI MANDAL
Attribute : Some of the methods are copied from GeeksforGeeks Website  */
import java.util.*;
import java.lang.*;
import java.io.*;
public class Main
{ 
  //static  Reader sc=new Reader();
   //static FastReader sc=new FastReader(System.in);
  static Scanner sc=new Scanner(System.in);
 public static void main (String[] args) throws java.lang.Exception
   {
	try{
	    /*
	        int n=sc.nextInt();
	        ArrayList<Integer> al=new ArrayList<>();
	        ArrayList<Long> al=new ArrayList<>();
	        Set<Integer> set=new HashSet<>();
	        Collections.sort(al,Collections.reverseOrder());
	     
	        long n=sc.nextLong();
	        for(int i=0;i<n;i++) 
	        String s=sc.next();
	     */
		  int t = 1;//sc.nextInt();
		  while(t-->0)
		    { 
		       
		      String s=sc.nextLine();
		      Set<Character> set=new HashSet<>();
		      int n=s.length();
		      for(int i=1;i<n-1;i+=3)
		        {
		           set.add(s.charAt(i));
		        }
		      out.println(set.size());
		    }
	     out.flush();
	     out.close();
	   }     
	catch(Exception e)
		 {}
	}
 
 /*
   ...SOLUTION ENDS HERE...........SOLUTION ENDS HERE...
 */
 
static void flag(boolean flag)
   {
       out.println(flag ? "YES" : "NO");
       out.flush();
   }
   
 /*                     
    Map<Long,Long> map=new HashMap<>();
             for(int i=0;i<n;i++)
               {
                  if(!map.containsKey(a[i]))
                   map.put(a[i],1);
                 else
                   map.replace(a[i],map.get(a[i])+1);
               }
     
    Set<Map.Entry<Long,Long>> hmap=map.entrySet();
             for(Map.Entry<Long,Long> data : hmap)
               {
          
               }
       
   Iterator<Integer> it = set.iterator();
          while(it.hasNext()) 
           { 
            int x=it.next();
           }
   */

static void print(int a[])
  {
     int n=a.length;
     for(int i=0;i<n;i++)
       {
          out.print(a[i]+" ");
       }
     out.println();
     out.flush();
  }
static void print(long a[])
  {
     int n=a.length;
     for(int i=0;i<n;i++)
       {
          out.print(a[i]+" ");
       }
     out.println();
     out.flush();
  } 
static void print_int(ArrayList<Integer> al)
  {
     int si=al.size();
     for(int i=0;i<si;i++)
       {
          out.print(al.get(i)+" ");
       }
     out.println();
     out.flush();
  }
static void print_long(ArrayList<Long> al)
  {
     int si=al.size();
     for(int i=0;i<si;i++)
       {
          out.print(al.get(i)+" ");
       }
     out.println();
     out.flush();
  }

static class Graph
  {
        int v;
        ArrayList<Integer> list[];
        Graph(int v)
        {
            this.v=v;
            list=new ArrayList[v+1];
            for(int i=1;i<=v;i++)
                list[i]=new ArrayList<Integer>();
        }
        void addEdge(int a, int b)
        {
            this.list[a].add(b);
        }
    }
static void DFS(Graph g, boolean[] visited, int u)
	{
        visited[u]=true;
        int v=0;
        for(int i=0;i<g.list[u].size();i++)
        {
            v=g.list[u].get(i);
            if(!visited[v])
               DFS(g,visited,v);
        }
  } 
  
// static class Pair
//    {
//       int x,y;
//       Pair(int x,int y)
//        {
//           this.x=x;
//           this.y=y;
//        }
//    }
   
static long sum_array(int a[])
 {
    int n=a.length;
    long sum=0;
    for(int i=0;i<n;i++)
     sum+=a[i];
    return sum;
 }
static long sum_array(long a[])
 {
    int n=a.length;
    long sum=0;
    for(int i=0;i<n;i++)
     sum+=a[i];
    return sum;
 }

 static void sort(int[] a) 
   {
		ArrayList<Integer> l=new ArrayList<>();
		for (int i:a) l.add(i);
		Collections.sort(l);
		for (int i=0; i<a.length; i++) a[i]=l.get(i);
	}
static void sort(long[] a) 
   {
		ArrayList<Long> l=new ArrayList<>();
		for (long i:a) l.add(i);
		Collections.sort(l);
		for (int i=0; i<a.length; i++) a[i]=l.get(i);
	}

static void reverse_array(int a[])
 {
    int n=a.length;
    int i,t; 
    for (i = 0; i < n / 2; i++) { 
            t = a[i]; 
            a[i] = a[n - i - 1]; 
            a[n - i - 1] = t; 
        } 
 }
static void reverse_array(long a[])
 {
    int n=a.length;
    int i; long t; 
    for (i = 0; i < n / 2; i++) { 
            t = a[i]; 
            a[i] = a[n - i - 1]; 
            a[n - i - 1] = t; 
        } 
 }
 
static long gcd(long a, long b) 
    { 
        if (a == 0) 
            return b; 
          
        return gcd(b%a, a); 
    } 
static int gcd(int a, int b) 
    { 
        if (a == 0) 
            return b; 
          
        return gcd(b%a, a); 
    } 

   static class FastReader{
 
        byte[] buf = new byte[2048];
        int index, total;
        InputStream in;
 
        FastReader(InputStream is) {
            in = is;
        }
 
        int scan() throws IOException {
            if (index >= total) {
                index = 0;
                total = in.read(buf);
                if (total <= 0) {
                    return -1;
                }
            }
            return buf[index++];
        }
 
        String next() throws IOException {
            int c;
            for (c = scan(); c <= 32; c = scan());
            StringBuilder sb = new StringBuilder();
            for (; c > 32; c = scan()) {
                sb.append((char) c);
            }
            return sb.toString();
        }
 
        int nextInt() throws IOException {
            int c, val = 0;
            for (c = scan(); c <= 32; c = scan());
            boolean neg = c == '-';
            if (c == '-' || c == '+') {
                c = scan();
            }
            for (; c >= '0' && c <= '9'; c = scan()) {
                val = (val << 3) + (val << 1) + (c & 15);
            }
            return neg ? -val : val;
        }
 
        long nextLong() throws IOException {
            int c;
            long val = 0;
            for (c = scan(); c <= 32; c = scan());
            boolean neg = c == '-';
            if (c == '-' || c == '+') {
                c = scan();
            }
            for (; c >= '0' && c <= '9'; c = scan()) {
                val = (val << 3) + (val << 1) + (c & 15);
            }
            return neg ? -val : val;
        }
    }
   
    static class Reader 
    { 
        final private int BUFFER_SIZE = 1 << 16; 
        private DataInputStream din; 
        private byte[] buffer; 
        private int bufferPointer, bytesRead; 
  
        public Reader() 
        { 
            din = new DataInputStream(System.in); 
            buffer = new byte[BUFFER_SIZE]; 
            bufferPointer = bytesRead = 0; 
        } 
  
        public Reader(String file_name) throws IOException 
        { 
            din = new DataInputStream(new FileInputStream(file_name)); 
            buffer = new byte[BUFFER_SIZE]; 
            bufferPointer = bytesRead = 0; 
        } 
  
        public String readLine() throws IOException 
        { 
            byte[] buf = new byte[64]; // line length 
            int cnt = 0, c; 
            while ((c = read()) != -1) 
            { 
                if (c == '\n') 
                    break; 
                buf[cnt++] = (byte) c; 
            } 
            return new String(buf, 0, cnt); 
        } 
  
        public int nextInt() throws IOException 
        { 
            int ret = 0; 
            byte c = read(); 
            while (c <= ' ') 
                c = read(); 
            boolean neg = (c == '-'); 
            if (neg) 
                c = read(); 
            do
            { 
                ret = ret * 10 + c - '0'; 
            }  while ((c = read()) >= '0' && c <= '9'); 
  
            if (neg) 
                return -ret; 
            return ret; 
        } 
  
        public long nextLong() throws IOException 
        { 
            long ret = 0; 
            byte c = read(); 
            while (c <= ' ') 
                c = read(); 
            boolean neg = (c == '-'); 
            if (neg) 
                c = read(); 
            do { 
                ret = ret * 10 + c - '0'; 
            } 
            while ((c = read()) >= '0' && c <= '9'); 
            if (neg) 
                return -ret; 
            return ret; 
        } 
  
        public double nextDouble() throws IOException 
        { 
            double ret = 0, div = 1; 
            byte c = read(); 
            while (c <= ' ') 
                c = read(); 
            boolean neg = (c == '-'); 
            if (neg) 
                c = read(); 
  
            do { 
                ret = ret * 10 + c - '0'; 
            } 
            while ((c = read()) >= '0' && c <= '9'); 
  
            if (c == '.') 
            { 
                while ((c = read()) >= '0' && c <= '9') 
                { 
                    ret += (c - '0') / (div *= 10); 
                } 
            } 
  
            if (neg) 
                return -ret; 
            return ret; 
        } 
  
        private void fillBuffer() throws IOException 
        { 
            bytesRead = din.read(buffer, bufferPointer = 0, BUFFER_SIZE); 
            if (bytesRead == -1) 
                buffer[0] = -1; 
        } 
  
        private byte read() throws IOException 
        { 
            if (bufferPointer == bytesRead) 
                fillBuffer(); 
            return buffer[bufferPointer++]; 
        } 
  
        public void close() throws IOException 
        { 
            if (din == null) 
                return; 
            din.close(); 
        } 
    }
  static  PrintWriter out=new PrintWriter(System.out);
  static int int_max=Integer.MAX_VALUE;
  static int int_min=Integer.MIN_VALUE;
  static long long_max=Long.MAX_VALUE;
  static long long_min=Long.MIN_VALUE;
}
// Thank You !